Buzzer.



J. A. WOTT-0N.,

BUZZER.

APPLICATION FILED 050.10. 1915.

1,292,207. Patented Jan. 21,1919.

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D STATES PATENT OFFICE.

JAMES A. WOT'ION, OF MONTCLAIR, NEW JERSEY, ASSIGN'OR '10 WESTERN ELECTRIC COMPANY, INCORPORATED, 013 NEW YORK, N. Y., A CORPORATION OF NEW'YORK.

BUZZER.

Specification of Letters Patent.

Patented Jan. 21, 1919.

Application filed December 10, 1915. Serial No. 66,181.

To all whom it may concern:

Be it known that I, JAMES A. WOTTON, a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Buzzers, of which the following is a full, clear, concise, and exact description.

This invention relates to electromagnetic devices or buzzers and more particularly to the details of construction tending to increase the general efficiency thereof.

A buzzer embodying the features of this invention comprises an electromagnet horizontally disposed, intermediate a pair of pole pieces. An armature is pivotally mounted upon one of said pole pieces and adapted to vibrate between the other pole piece and an extension member carried thereby. Adjusting means are provided for regulating both the air-gap between the armature and the pole piece, and the frequency of its vibration, as will hereinafter be described.

In the accompanying drawing, Figure 1 is a lan of a buzzer embodying the features of t is invention; Fig. 2 is a side elevation of the device shown in Fig. 1; and Fig. 3 illustrates diagrammatically the energizing circuits for actuating the same.

A buzzer made in accordance with this invention comprises an electromagnet 1 horizontally disposed, intermediate a pair of an gular pole pieces 2, 3 secured to a resonant base 4: by means of screws entering from the underside thereof. The vertical end of the pole piece 2 is provided with a knife edge adapted to register with a groove formed in an armature 5 so as to afford a pivotal mounting for said armature. The free end of the armature 5, when attracted upon the energization of the electromagnet 1, strikes the end of the pole piece 3. Mounted adj acent the pole piece 3, but electrically separated therefrom, is a heel piece 6. The same screw may suflice to maintain the heel piece 6 and the right-hand end of the electromagnet 1 in their respective positions. The u er end of the heel piece 6 carries a back-stop screw 7 and a contact set screw 8, the former functioning as a means to regulate the air gap between the end of the pole piece 3 and the armature 5; the latter serving for adjusting the contact relation between itself and a contact spring member 9 carried by the armature 5. A helical spring 10 is attached to the fixed end of the armature 5, the tension of which is adjustable by movmg vertically the fastening piece 11 to which its other end is anchored. This spring functions both as a retractile spring and as a holding spring to firmly seat the armature on its supporting knife edge. The fastening plece 11 is provided at its upper end with. tongue portion 12 adapted to extend through an aperture in the armature 5, thus preventing the sidewise dislocation of the armature from its pivotal mounting. An armature mounting is thereby provided in which there 1s intimate connection between the pole piece and the armature, and in which the armature is easily removable without the use of external appliances such as a screw driver or wrench. Its removal is accomplished merely by swinging it from between the pole piece 3 and the heel piece 6, and lifting it clear of the tongue portion 12. This method of mounting the armature has been found to be very satisfactory, in that it is both simple to manufacture and assemble and easily disassembled for repair work such as to clean the knife edge or to replace the contact spring.

Binding posts 13, 14 and 15 are provided for connecting the buzzer in an energizing circuit. The binding post 13 is connected by a conductor 16 to the heel piece 6, and, when direct current is used for operating the buzzer, it traverses the following path: post 14:, winding of electromagnet 1, post 13, heel piece 6, contact member 9, to post 15. When alternating current is employed, connection may be made with posts 13 and 14.

The preferred adjustment of the armature 5 is to have the back-stop screw 7 set so that it will arrest the backward movement of said armature without its being cushioned through the flexure of the contact member 9 engaging the contact set screw 8. The adjusting of the contact relation between the contact spring 9 and the set screw 8 is such that these members make contact just before the armature 5 has reached the end of its backward movement. These adjustments permit the armature 5, when vibrating to strike forcibly against the pole piece 3 and the back stop screw 7, thereby greatly adding to the efiiciency of the sound producing properties of the buzzer. The frequency of the vibration of the armature 5 may be varied by regulating the set screw 7 and the tension of the spring 10. 1

From the above, it will be apparent that a buzzer made in accordance With this invention is. simple in construction, easy to maintain in adjustment and efficient in operanion; i

What is claimed is:

1. In a buzzer, in combination, a base, an electromagnet, pole pieces for the electromagnet mounted upon the base for supporting the electromagnet, an angular extension onvon'e' end of'one of the pole pieces, an armature pivotally mounted on the other pole piece with its free end in position to vibratexbetweensuch pole piece and the angular extension thereof, and to make mechanical contact With both said extension and pole-piece, whereby an audible tone is produced. v f 2. In an electromagnetic device, a base, an fiL shaped pole piece having one leg secured to the base and a second leg provided With akliife edge, an electromagnet secured to said second leg, a unitary member compris- 'iflopies' of-thia patentmay be obtained. for

five cents each, by addressing the tiommiasioner of Washington, D. t3.

ing a body portion adapted to slide along said second leg, a spring lug and a tongue portion, said unitary member being adjustaly secured to said second leg, an armature pivotally supported on said knife edge, an aperture in said armature through Which said tongue portion extends, and a retractile spring secured to said armature and said spring lug. Y

3. In an electromagnetic device, an, elec: tromagnet, a pole piece secured thereto hay ing a knife edge, an armature therefor pivotally mounted on said knife edge, a second pole piece in attractive relation to the armature, a retractile spring secured to the an mature, an adjustable member comprising-a spring lug and a tongue portion, said adjustable member being adjustably secured to said first-mentionedpole-piece, said tongue portion cooperating With the armature to removably position said armature on knife edge support.

In witness whereof, I hereunto subscribe my name this 9th day of December, A. Di

JAMES A. WOTTON. 2

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Patents, 

